This is the second revised resubmission to utilize a transgenic (tg) model we developed to study the pathogenesis of chronic wasting disease (CWD) of deer and elk. At the last review the grant received a 13% score, not sufficient for funding. To enhance the competitiveness of this grant, of the two previous specific aims, only the one that was considered with the highest enthusiasm was retained. That aim was to determine the tissue distribution and titers of infectious deer scrapie inoculated into tg mice that have their murine PrP gene ko and replaced by deer PrP controlled by murine PrP promoter. When not treated or given murine scrapie, such tg mice do not develop disease over 600+ days. In contrast, when inoculated i.e. or orally with brains from deer with CWD, they developed classic TSE disease within 200 to 230 and 350 to 365 days, respectively. CWD is a transmissible spongiform encephalopathy (TSE, prion disease, scrapie). TSE diseases are rare, fatal neurodegenerative illness of humans and other animals. A recent concern has been TSE disease of cervids. The majority of deer on farms (in some cases -80%) as well as 20% of deer and 1% of elk free in the field develop CWD. How the disease is transmitted and if humans (hu) can be infected are unknown. The potential danger is underscored by in vitro studies in which normal hu PrPsen, when mixed with CWD PrPres can be converted to the hu disease form (hu PrPres). To address the issue of transmission, pathogenesis and eventual treatment, we successfully generated tg mice that can be used to assay infectivity of deer tissue. To reach this goal we have obtained samples of saliva, blood, plasma, buffy coat cells, urine, feces, tonsils, lymph nodes, spleen, skeletal muscle and brain collected at defined intervals from deer/elk. Materials were collected from deer either experimentally inoculated with deer scrapie until they became moribund and were sacrificed as well as samples from captive deer naturally infected in the field. Our hypothesis is that the inoculation of these materials in our tg mice will allow us to: 1) determine which body excreta, fluids or tissues contain infectious deer scrapie; 2) quantitate the levels of infectivity in these samples; 3) utilize results in 1) & 2) to determine the likely ways deer scrapie is/can be transmitted from one animal to another; 4) begin to use this data to understand the pathogenesis and eventual control of CWD. [unreadable] [unreadable] [unreadable]